M2.5 hit the bottom teeth with much bit
Then, the chip 2.5-0.45=2.05 is used to tap bottom drill bit drilling. If it is an extrusion tap, the formula is 2.5-0.45/2=2.275's drill.
M2.5 is the diameter, you want to use this diameter to subtract the distance of the tooth, that is, the diameter of the drill. In the metric system, the distance of M2.5 is 0.45.
